The Nickel (Ni)-NTA Agarose Resin consists of beads of highly cross-linked 6% Agarose, coupled with Nitrilotriacetic acid (NTA). NTA is a tetravalent chelating agent, covalently coupled to cross-linked agarose beads, providing a higher specificity and lower ion leaching than IDA linked resins. The Ni-NTA Resin can be used to purify 6x His-tagged proteins expressed in series of expression vectors, such as E.coli., yeast, insect cells and mammalian cells. NTA resins have also been shown to be more robust in the presence of higher concentrations of EDTA, but may require a higher imidazole concentration for protein elution. This resin is loaded with Ni2+ and is ideal for rapid purifications of His-tagged proteins. The structure of Ni-NTA is compatible with a certain concentration of reducing agents, denaturing agents, detergents and other additives.